Twenty-one years ago, I began my quest to catch sailfish on a fly rod in Costa Rica. Over the intervening years, Jenny, my wife, and I traveled to Costa Rica January through March as this is considered the “high season” for sailfish in Central America. During that first quarter of the year, the fishing was great, and we caught a lot of sailfish on the fly and a few marlin, yellowfin tuna, and dorado as well. When our children reached the age at which we could take them with us, we began fishing in the summer months as well. However, we never caught as many sailfish in July as in the earlier months. In my amateur scientific mind, a migration pattern was at work here, and I wanted to find out what was going on.
I spent many days on the boat talking to the mate Marco and Captain Jose about sailfish migration, and it was clear that they didn’t know where the sailfish were going. I asked other captains and mates around the port town of Quepos, and they didn’t know either.
About seven years ago, I decided to try to figure out this migration puzzle. I formed The Billfish Research Project and enlisted the help of my friend and retired marine science professor John Mark Dean, Ph.D. Nothing was conclusive in the scientific literature about sailfish migration, so we figured we would have to undertake this research ourselves. We knew that conventional plastic “spaghetti” tags offered little to no insight and that researchers were already using Pop-Up Satellite Tags on other highly migratory species like great white sharks and bluefin tuna. I tasked Dr. Dean with sourcing some tags for our use and went about raising some funds to acquire them. By December 2011, we had our tags and were ready to start figuring out sailfish migration.
As part of the process of tagging sailfish, we developed protocols to ensure the safety of both the sailfish and our team, keeping in mind that a mature sailfish is 90 pounds of muscle with a very sharp bill on its head! Therefore, we had to develop specific procedures for handling the fish at the boat, inserting the tag into a specific spot near the base of the dorsal fin, and taking care to promptly release the fish to swim off and collect data in the PSAT.
These PSATs were programmed to collect data on geolocation, water temperature, and depth for a specific period of time, after which they would detach from the fish, float to the surface, and begin transmitting the collected data to a satellite in orbit. Our team was expanded to include several Ph.D. scientists to download and interpret the data. Once the data started to accumulate, we began to get a picture of sailfish migration. It appears that in the short term, sailfish arrive off the Pacific Coast of Costa Rica in December and remain there until late April, at which time they take off in various directions but principally migrate way offshore.
From the very beginning of our tagging expeditions, we enlisted the help of photographers and videographers to document the tagging process both above and below the surface. Team member Lawson Barnes has done a terrific job of documenting the release of sailfish once they have been tagged. The video footage he has obtained shows us the health of the fish and how water flows over the tag. This is vital information both for us as well as the tag manufacturer.
We simply don’t know why these sailfish leave the coastal waters of Costa Rica and head way offshore, but we can begin to make some guesses. The current hypothesis is that they are heading offshore to produce their young. Many more predators are located inshore than far offshore. It may be as simple as that. In 21 seasons of fishing Costa Rica, we have never caught a juvenile sailfish. So where are they? Where are they born? Where is their nursery? Answers to questions like these can help fishery managers develop proper regulations to sustain the sailfish population.
Further work remains to be done. Our team continues to ask questions, develop research strategies, and push forward the depth of knowledge about the life history of sailfish off the Pacific Coast of Costa Rica. For additional information and some exceptional video pieces, visit our website, BillfishResearch.org.
The adventure continues …
Jamie Walker, who grew up in Columbia, has had a lifelong obsession with salt water and the many animals that inhabit its shallows and offshore depths and ride the air currents above. As a photographer, fisherman, and sailor, Jamie has had many interactions with these animals and their beautiful surroundings. Over the past several years Jamie has spent many days at sea working on The Billfish Research Project. Base camp for Jamie is still in Columbia, where he lives with Jenny, his wife, and a bunch of black labs.